<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>本页面用于演示外边距折叠(Collapsing margins)-第一到第三种计算方式</title>
		<link rel="stylesheet" href="css/1.css" type="text/css" />
		<style type="text/css">
			.red, .yellow, .blue{
				width: 100px;
				height: 100px;
				
			}
			.red {
				border: red solid 1px;
				background-color: #006400;
				margin-bottom: -50px;
			}
			.yellow{
				border: yellow solid 1px;
				background-color: #8B0000;
				margin-top: 100px;
			}
			.blue {
				border: blue solid 1px;
			    background-color: #CD5C5C;
			}
		</style>
	</head>
	<body>
		<div class="red"></div>
		<div class="yellow"></div>
		<div class="blue"></div>
		
		
		
	</body>
</html>
